Gated Image Acquisition And Patient Model Construction

ABSTRACT

A method and system is disclosed for acquiring image data of a subject. The image data can be collected with an imaging system with at least two different power characteristics. The image data can be reconstructed using dynamic or enhanced reconstruction techniques.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 12/908,200 filed on Oct. 20, 2010. The entire disclosure of the above application is incorporated herein by reference.

FIELD

The present disclosure relates to imaging a subject, and particularly to determining and performing an optimal image data acquisition of the subject to model various physiological characteristic and anatomical features of the subject.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

A subject, such as a human patient, may select or be required to undergo a surgical procedure to correct or augment an anatomy of the patient. The augmentation of the anatomy can include various procedures, such as movement or augmentation of bone, insertion of implantable devices, or other appropriate procedures. A surgeon can perform the procedure on the subject with images of the patient that can be acquired using imaging systems such as a magnetic resonance imaging (MRI) system, computed tomography (CT) system, fluoroscopy (e.g. C-Arm imaging systems), or other appropriate imaging systems.

Images of a patient can assist a surgeon in performing a procedure including planning the procedure and performing the procedure. A surgeon may select a two dimensional image or a three dimensional image representation of the patient. The images can assist the surgeon in performing a procedure with a less invasive technique by allowing the surgeon to view the anatomy of the patient without removing the overlying tissue (including dermal and muscular tissue) when performing a procedure.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

According to various embodiments, a system to acquire image data of a patient with an imaging system using enhanced contrast imaging can include an imaging system having a first energy source with a first energy parameters and a second energy source with a second energy parameters. The imaging system can also include a pump operable to inject a contrast agent into the patient with an instruction. A controller can be in communication with both the imaging system and the pump. The imaging system can communicate with the pump through the controller regarding timing of the injection of a contrast agent into the patient and is further operable to acquire image data based upon the timing of the injection of the contrast agent and/or the clinical procedure.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is an environmental view of an imaging system in an operating theatre;

FIG. 2 is a detail view of an imaging system with a dual energy source system;

FIG. 3A is a schematic representation of non-contrast enhanced image data; and

FIG. 3B is a schematic representation of a contrast enhanced image data.

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings.

With reference to FIG. 1, in an operating theatre or operating room 10, a user, such as a surgeon 12, can perform a procedure on a patient 14. In performing the procedure, the user 12 can use an imaging system 16 to acquire image data of the patient 14 for performing a procedure. A model can be generated using the image data and displayed as image data 18 on a display device 20. The display device 20 can be part of a processor system 22 that includes an input device 24, such as a keyboard, and a processor 26 which can include one or more processors or microprocessors incorporated with the processing system 22. A connection 28 can be provided between the processor 26 and the display device 20 for data communication to allow driving the display device 20 to illustrate the image data 18.

The imaging system 16 can include an O-Arm® imaging system sold by Medtronic Navigation, Inc. having a place of business in Louisville, Colo., USA. The imaging system 16, including the O-Arm® imaging system, or other appropriate imaging systems in use during a selected procedure are also described in U.S. patent application Ser. No. 12/465,206 filed on May 13, 2009, incorporated herein by reference.

The O-Arm® imaging system 16 includes a mobile cart 30 that includes a control panel or system 32 and an imaging gantry 34 in which is positioned a source unit 36 and a detector 38. The mobile cart 30 can be moved from one operating theater to another and the gantry 34 can move relative to the cart 30, as discussed further herein. This allows the imaging system 16 to be mobile thus allowing it to be used in multiple locations and with multiple procedures without requiring a capital expenditure or space dedicated to a fixed imaging system.

The source unit 36 can emit x-rays through the patient 14 to be detected by the detector 38. As is understood by one skilled in the art, the x-rays emitted by the source 36 can be emitted in a cone and detected by the detector 38. The source/detector unit 36/38 is generally diametrically opposed within the gantry 34. The detector 38 can move in a 360° motion around the patient 14 within the gantry 34 with the source 36 remaining generally 180° opposed to the detector 38. Also, the gantry 34 can move isometrically relative to the subject 14, which can be placed on a patient support or table 15, generally in the direction of arrow 40 as illustrated herein. The gantry 34 can also tilt relative to the patient 14 illustrated by arrows 42, move longitudinally along the line 44 relative to a longitudinal axis 14L of the patient 14 and the cart 30, can move up and down generally along the line 46 relative to the cart 30 and transversely to the patient 14, to allow for positioning of the source/detector 36/38 relative to the patient 14. The O-Arm® imaging device 16 can be precisely controlled to move the source/detector 36/38 relative to the patient 14 to generate precise image data of the patient 14. The imaging device 16 can be connected with the processor 26 via connection 50 which can include a wired or wireless connection or physical media transfer from the imaging system 16 to the processor 26. Thus, image data collected with the imaging system 16 can be transferred to the processing system 22 for navigation, display, reconstruction, etc.

Briefly, according to various embodiments, the imaging system 16 can be used with an unnavigated or navigated procedure. In a navigated procedure, a localizer, including either or both of an optical localizer 60 and an electromagnetic localizer 62 can be used to generate a field or receive or send a signal within a navigation domain relative to the patient 14. The navigated space or navigational domain relative to the patient 14 can be registered to the image data 18 to allow registration of a navigation space defined within the navigational domain and an image space defined by the image data 18. A patient tracker or dynamic reference frame 64 can be connected to the patient 14 to allow for a dynamic registration and maintenance of registration of the patient 14 to the image data 18.

A patient tracking device or dynamic registration device 64 and an instrument 66 can then be tracked relative to the patient 14 to allow for a navigated procedure. The instrument 66 can include an optical tracking device 68 and/or an electromagnetic tracking device 70 to allow for tracking of the instrument 66 with either or both of the optical localizer 60 or the electromagnetic localizer 62. The instrument 66 can include a communication line 72 with a navigation interface device 74 as can the electromagnetic localizer 62 with communication line 76 and/or the optical localizer 60 with communication line 78. Using the communication lines 74, 78 respectively, the probe interface 74 can then communicate with the processor 26 with a communication line 80. It will be understood that any of the communication lines 28, 50, 76, 78, or 80 can be wired, wireless, physical media transmission or movement, or any other appropriate communication. Nevertheless, the appropriate communication systems can be provided with the respective localizers to allow for tracking of the instrument 66 relative to the patient 14 to allow for illustration of the tracked location of the instrument 66 relative to the image data 18 for performing a procedure.

It will be understood that the instrument 66 being any appropriate instrument, such as a ventricular or vascular stent, spinal implant, neurological stent or stimulator, ablation device, or the like. The instrument 66 can be an interventional instrument or can include or be an implantable device. Tracking the instrument 66 allows for viewing the instrument's 66 location relative to the patient 14 with use of the registered image data 18 without direct viewing of the instrument 66 within the patient 14.

Further, the gantry 34 can include an optical tracking device 82 or an electromagnetic tracking device 84 to be tracked with a respective optical localizer 60 or electromagnetic localizer 62. Accordingly, the imaging device 16 can be tracked relative to the patient 14 as can the instrument 66 to allow for initial registration, automatic registration or continued registration of the patient 14 relative to the image data 18. Registration and navigated procedures are discussed in the above incorporated U.S. patent application Ser. No. 12/465,206.

With reference to FIG. 2, according to various embodiments, the source 36 can include a single x-ray tube 100 that can be connected to a switch 102 that can interconnect a power source A 104 and a power source B 106 with the x-ray tube 100. X-rays can be emitted generally in a cone shape 108 towards the detector 38 and generally in the direction of the vector 110. The switch 102 can switch between the power source A 104 and the power source B 106 to power the x-ray tube 100 at different voltages and amperages to emit x-rays at different energies generally in the direction of the vector 110 towards the detector 38. It will be understood, however, that the switch 102 can also be connected to a single power source that is able to provide power at different voltages and amperages rather than the 102 switch that connects to two different power sources A 104, and B 106. Also, the switch 102 can be a switch that operates to switch a single power source between different voltages and amperages. The patient 14 can be positioned within the x-ray cone 108 to allow for acquiring image data of the patient 14 based upon the emission of x-rays in the direction of vector 110 towards the detector 38.

The two power sources A and B 104, 106 can be provided within the source housing 36 or can be separate from the source 36 and simply be connected with the switch 102 via appropriate electric connections such as a first cable or wire 112 and a second cable or wire 114. The switch 102 can switch between the power source A 104 and the power source B 106 at an appropriate rate to allow for emission of x-rays at two different energies through the patient 14 for various imaging procedures, as discussed further herein. The differing energies can be used for material separation and/or material enhanced reconstruction or imaging of the patient 14.

The switching rate of the switch 102 can include about 1 millisecond to about 1 second, further including about 10 ms to 500 ms, and further including about 50 ms. Further, the power source A 104 and the power source B 106 can include different power characteristics, including different voltages and different amperages, based upon selected contrast enhancement requirements. For example, as discussed further herein, it can be selected to allow for contrast enhancement between soft tissue (e.g. muscle or vasculature) and hard tissue (e.g. bone) in the patient 14 or between a contrast agent injected in the patient 14 and an area without a contrast agent injected in the patient 14.

As an example, the power source A 104 can have a voltage of about 75 kV and can have an amperage of about 50 mA, which can differ from the power source B which can have a voltage of 125 kV and 20 mA. The selected voltages and amperages can then be switched with the switch 102 to power the x-ray tube 100 to emit the appropriate x-rays generally in the direction of the vector 110 through the patient 14 to the detector 38. It will be understood that the range of voltages can be about 40 kV to about 80 kV and the amperages can be about 10 mA to about 500 mA. Generally, the power characteristics differences between the first power source A 104 and the second power source B 106 can be about 40 kV to about 60 k V and about 20 mA to about 150 mA.

The dual power sources allow for dual energy x-rays to be emitted by the x-ray tube 100. As discussed above, the two or dual energy x-rays can allow for enhanced and/or dynamic contrast reconstruction of models of the subject 14 based upon the image data acquired of the patient 14. Generally an iterative or algebraic process can be used to reconstruct the model of at least a portion of the patient 14 based upon the acquired image data. It will be understood, however, that any appropriate number of power sources or switching possibilities can be provided. Two is included in the subject disclosure merely for clarity of the current discussion.

The power sources can power the x-ray tube 100 to generate two dimension (2D) x-ray projections of the patient 14, selected portion of the patient 14, or any area, region or volume of interest. The 2D x-ray projections can be reconstructed, as discussed herein, to generate and/or display three-dimensional (3D) volumetric models of the patient 14, selected portion of the patient 14, or any area, region or volume of interest. As discussed herein, the 2D x-ray projections can be image data acquired with the imaging system 16, while the 3D volumetric models can be generated or model image data.

Appropriate algebraic techniques include Expectation maximization (EM), Ordered Subsets EM (OS-EM), Simultaneous Algebraic Reconstruction Technique (SART) and Total Variation Minimization (TVM), as generally understood by those skilled in the art. The application to performing a 3D volumetric reconstruction based on the 2D projections allows for efficient and complete volumetric reconstruction. Generally, an algebraic technique can include an iterative process to perform a reconstruction of the patient 14 for display as the image data 18. For example, a pure or theoretical image data projection, such as those based on or generated from an atlas or stylized model of a “theoretical” patient, can be iteratively changed until the theoretical projection images match the acquired 2D projection image data of the patient 14. Then, the stylized model can be appropriately altered as the 3D volumetric reconstruction model of the acquired 2D projection image data of the selected patient 14 and can be used in a surgical intervention, such as navigation, diagnosis, or planning. The theoretical model can be associated with theoretical image data to construct the theoretical model. In this way, the model or the image data 18 can be built based upon image data acquired of the patient 14 with the imaging device 16.

The 2D projection image data can be acquired by substantially annular or 360° orientation movement of the source/detector 36/38 around the patient 14 due to positioning of the source/detector 36/38 moving around the patient 14 in the optimal movement. Also, due to movements of the gantry 34, the detector need never move in a pure circle, but rather can move in a spiral helix, or other rotary movement about or relative to the patient 14. Also, the path can be substantially non-symmetrical and/or non-linear based on movements of the imaging system 16, including the gantry 34 and the detector 38 together. In other words, the path need not be continuous in that the detector 38 and the gantry 34 can stop, move back the direction from which it just came (e.g. oscilate), etc. in following the optimal path. Thus, the detector 38 need never travel a full 360° around the patient 14 as the gantry 34 may tilt or otherwise move and the detector 38 may stop and move back in the direction it has already passed.

In acquiring image data at the detector 38, the dual energy x-rays generally interact with a tissue and/or a contrast agent in the patient 14 differently based upon the characteristics of the tissue or the contrast agent in the patient 14 and the energies of the two x-rays emitted by the x-ray tube 100. For example, the soft tissue of the patient 14 can absorb or scatter x-rays having an energy produced by the power source A 104 differently than the x-rays having energy produced by the power source B 106. Similarly, a contrast agent, such as iodine, can absorb or scatter the x-rays generated by the power source A 104 differently from those generated by the power source B 106. Switching between the power source A 104 and the power source B 106 can allow for determination of different types of material properties (e.g. hard or soft anatomy), or contrast agent, implants, etc. within the patient 14. By switching between the two power sources 104, 106 and knowing the time when the power source A 104 is used to generate the x-rays as opposed to the power source B 106 to generate the x-rays the information detected at the detector 38 can be used to identify or segregate the different types of anatomy or contrast agent being imaged.

A timer can be used to determine the time when the first power source A 104 is being used and when the second power source B 106 is being used. This can allow the images to be indexed and separated for generating different models of the patient 14. Also, as discussed herein, the timer, which can be a separate system or included with the imaging system 16 or the processor system 26, can be used to index image data generated with the contrast agent injected into the patient 14.

With reference to FIG. 3A, image data acquired when powering the x-ray tube 100 with the power source 104 is schematically illustrated. As illustrated in FIG. 3A, the image data can include image data of soft tissue, such as surrounding tissues 150 that surround a vasculature 152. As illustrated in FIG. 3A, the power source A 104 can generate x-rays of the x-ray tube 100 that provide substantially little contrast between the vasculature 152 and the surrounding tissue 150, even if a contrast agent is present in the vasculature agent 152, such as iodine. With reference to FIG. 3B, however, the second power source B 106 can be used to generate x-rays with a second energy characteristic to acquire image data that illustrates the surrounding tissue 150′ relative to the vasculature 152′. This can be further enhanced with a contrast agent that can be injected into the patient 14. As is understood in the art, the two power levels (e.g. two or more power characteristics) have different attenuations based on the materials in the patient 14. This differing attenuation can be used to differentiate materials, e.g. vasculature 152 and the surrounding tissue 150, in the patient 14.

With the acquisition of the image data illustrated in FIG. 3A and FIG. 3B, a reconstruction can be made to clearly identify the vasculature 152 of the patient 14 separate from the surrounding tissue 150 of the patient 14. The dual energy system can be used to reconstruct a model of the vasculature 152 of the patient 14 to discriminate the vasculature 152 from the surrounding tissue 150 of the patient 14. In identifying the vasculature 152, the imaging system 16, including the O-Arm® imaging system, can be used to efficiently image the vasculature 152 of the patient 14 in the operating theatre 10 during a procedure, such as a valve replacement procedure, a stent procedure, an inclusion ablation procedure, or an angioplasty procedure.

At least because the x-ray tube 100 is in a movable imaging system, such as the imaging system 16, it can be moved relative to the patient 14. Thus, the x-ray tube 100 may move relative to the patient 14 while the energy for the x-ray tube 100 is being switched between the first power source 104 and the second power source 106. Accordingly, an image acquired with the first power source 104 may not be at the same pose or position relative to the patient 14 as the second power source 106. If a model is desired or selected to be formed of a single location in the patient 14, however, various interpolation techniques can be used to generate the model based on the amount of movement of the x-ray tube 100 between when the projection with the first power source 104 and the projection with the second power source 106 was acquired.

The dual energy of the x-rays emitted by the x-ray tube 100 due to the two power sources 104, 106 can allow for substantially efficient and enhanced contrast discrimination determination between the vasculature 152 and the musculature 150 of the patient 14. Moreover, the switching by a switch 102 between the power source A 104 and the power source B 106 allows for an efficient construction of the source 36 where the single x-ray tube 100 can allow for the generation of x-rays at two different energies to allow for enhanced or dynamic contrast modeling of the patient 14, such as modeling the vasculature of the patient 14 including a contrast agent therein.

The patient 14 can also be imaged with the injected contrast agent by gating the acquisition of the image data of the patient 14 based upon the injection of the contrast agent. According to various embodiments, a contrast agent, such as iodine, can be injected into the patient 14 to provide additional contrast in the image data acquired of the patient 14 with the imaging system 16. During the image acquisition, however, the contrast agent flows through the vasculature of the patient 14 from an artery phase to a venous phase. For example, the contrast agent can be injected into the patient 14 into an artery where the contrast agent can flow through the vasculature of the patient 14 to the heart, through the heart, to the lungs through the venous system, back through the heart, and out into the arterial portion of the vasculature of the patient 14.

When acquiring image data of the patient 14 to identify or reconstruct the vasculature of the patient 14, knowing the timing of when image data is acquired relative to the timing of the injection of the contrast agent can allow for a reconstruction of the various phases based on the known movement of the contrast agent through structures of the patient 14. In other words, it is generally understood that the contrast agent will flow through the patient 14 as described above at a known or generally known rate. As illustrated in FIG. 3B, the dual energy x-rays, generated with the x-ray tube 100 based upon the power source A 104 and the power source B 106, can be used to generate image data of any portion of the vasculature of the patient 14.

The acquisition of the image data, therefore, can be gated relative to the injection of the contrast agent into the patient 14. For example, the controls 32 of the imaging system 16 can be associated or communicate with a control of a pump 170 (illustrated in FIG. 1) through a communication line 172 (illustrated in FIG. 1) that pumps or injects the contrast agent into the patient 14. The communication 172 between the pump 170 and the imaging device control 32 can be any appropriate communication such as a wired, wireless, or other data communication system. Also, the control 170 for the pump can be incorporated into the controls 32 of the imaging system 16 or the processor system 26.

According to various embodiments, the control system 32 for the imaging system 16 can control the pump 170 to initiate injection of the contrast agent into the patient 14. The imaging system 16 can then acquire image data of the patient 14 over a set period of time to identify the difference between an arterial phase and a venous phase in the patient 14. For example, the imaging system can control the pump 170 to inject the contrast agent and then acquire image data for approximately 10 seconds to approximately 20 second including approximately 13 seconds. The imaging system 16 can identify or separate a first portion of the image data, such as about 5 second to about 7 seconds, including about 6 seconds as an arterial phase and a second phase of the image data, such as image data acquired after about 6 second to about 8 seconds, including about 7 seconds as a venous phase. In other words, the control system 32, or other appropriate processor system, can index the image data to determine when the image data was acquired. Also, it will be understood that the image data can be acquired at the two energies. Thus, the controls 32 or other appropriate processing system (e.g. a timer) can index the image data based on which of the two power sources 104, 106 were used to power the x-ray tube 100.

After the acquisition of the image data and determining a segregation of time of image data acquisition, a reconstruction of the vasculature of the patient 14 can then be made to illustrate or identify or reconstruct an arterial phase of the patient 14 and separately a venous phase of the patient 14. Accordingly, the imaging system 16 controlled with the controller 32 can be used to acquire image data of both a venous phase and an arterial phase of the patient 14 in a single image data acquisition sweep or period. In other words, the phase determination and reconstruction of an arterial phase and a venous phase of the vasculature of the patient 14 can be based on a single image data acquisition phase of the patient 14. Again, this can minimize or limit the exposure of the patient 14 and operating room staff to x-rays emitted from the x-ray tube 100 by requiring only a single image data acquisition phase. It will be understood, however, that a plurality of image data acquisition phases can be acquired of the patient 14.

The control system 32 of the imaging system 16 can be used to gate acquisition of the image data in addition to or with timing of the pump 170. For example, it can be selected to acquire image data of the vasculature of the patient 14 during diastole of the heart. During diastole of the heart of the patient 14, the heart generally does not move and blood in the vasculature is also relatively still. Accordingly, the image data can be acquired of the patient 14 by gating the acquisition of the image data relative to the heart movement of the patient 14. The generation of the x-rays with the x-ray tube 100 can be switched with the switch 102 to allow for time emission of x-rays from the x-ray tube 100.

The image data can be acquired by emitting x-rays from the x-ray tube 100 substantially sequentially such that at a selected period of time no x-rays are emitted by the x-ray tube 100 and at a different or second selected time x-rays are emitted from the x-ray tube 100. The x-rays emitted from one period to another can be at either of the two energies allowed by the power source A 104 or the power source B 106. Accordingly, at various times no x-rays can be emitted from the x-ray tube 100, but at other times x-rays can be emitted from the x-ray tube at a selected energy.

In being able to control the image system to emit or not emit x-rays image data acquisition can be gated relative to a physiological event of the patient 14. It will be further understood that gating of the image acquisition can be based upon respiration of the patient 14, physical movement of the patient 14, and other physiological events. The control system 32 can also be used to index the image data regarding whether acquired during a physiological event or not. The physiological event can be determined with an appropriate system, such as an electrocardiogram, or based on a regular rate of image acquisition (e.g. diastole occurs about 2 seconds in the patient 14).

Also, due to gating of the imaging system 16 relative to the patient 14, the control system 32 can also be used to control the imaging system 16 to control the speed of the detector 38 relative to the patient 14. As discussed above, the detector 38 of the imaging system can translate within the gantry 34 of the imaging system 16 to acquire image data of the patient 14. Further as discussed above, image data can be selected to be acquired of the patient 14 during only selected physiological events, such as diastole of the heart. To generate or form a three-dimensional model of at least a portion of the patient 14, it can be selected to have separation of a selected amount between acquisitions of images of the patient 14.

The detector 38 can be moved at a selected speed and change speeds to ensure appropriate separation of the images during the selected physiological events. The detector 38 can move at a first speed during a first physiological event such as systole of the heart, and at a second speed, such as a greater speed, during diastole of the heart to ensure appropriate separation of acquisition of images of the patient 14 during the selected physiological event.

In generating the 3D volumetric reconstruction to form the model, as discussed above, the model may be multi-phase to illustrate a selected portion of the patient to illustrate a first phase of physiological action and anatomical location and a second phase of physiological action and anatomical location. Thus, the model, or more than one model, can be used to illustrate a first phase (e.g. an arterial phase) and a second phase (e.g. venous phase) of the patient 14. Also, due to gating and movement of the detector 38 a first position of the detector 38 during image data acquisition and a second position of the detector 38 during image data acquisition can be used in the generating the first model and generating the second model to illustrate more than one phase of a physiological action of the patient 14. Additionally, the anatomy of the patient 14 and the physiology of the patient 14 can be used to form the 3D reconstruction. For example, the configuration of a bone of the patient 14 or a phase of a heart beat of the patient 14 can be used as a priori knowledge to assist in model reconstruction.

Also, the controller 32 of the imaging system 16 can be used to “rewind” or move the detector 38 back over the same path just traversed by the detector 38. Even while moving in a selected single path or direction, the detector 38 can be stopped and started, for example for gating or acquiring additional image data (e.g. x-ray projections) at a selected location. Accordingly, the controller 32 can control the imaging system 16 to achieve a selected separation of images relative to the patient 14 for reconstruction of an appropriate or selected model of the patient 14 based upon the required image data.

The reconstruction based on the image data or the raw image data can be used to perform a procedure on the patient 14. As discussed above selected navigation or tracking systems can be associated with the imaging system 16. Accordingly, the patient 14 can be registered to the image data and a navigation procedure can be performed. The navigated procedure can include placement of a stent in the patient's 14 heart, brain, or other vasculature, ablation procedures, angioplasty, implant placement or bone resection. Navigation can include tracking or determining automatically a location of an instrument positioned in a navigation field relative to a selected reference frame, such as in patient space, during a surgical procedure. The location of the instrument 66 can be illustrated on the display device 20 with an icon 174 that can be superimposed on the image data or the reconstructed model or image data 18.

It will also be understood that the image data and/or model can be used to plan or confirm a result of a procedure without requiring or using navigation and tracking. The image data can be acquired to assist in a procedure, such as an implant placement. Also, the image data can be used to identify blockages in the vasculature of the patient 14, such as with the contrast agent. Thus, navigation and tracking are not required to use the image data in a procedure.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention. 

What is claimed is:
 1. A method of acquiring image data with an imaging system, comprising: providing a first power source to power a single x-ray source tube with a first power characteristic to emit x-rays to acquire a first image data relative to a first selected position for acquisition of a first image data; providing a second power source to power the single x-ray source tube with a second power characteristic different from the first power characteristic to emit x-rays to acquire a second image data relative to the first selected position; providing a moving system to move the single x-ray source tube during the acquisition of the first image data and the second image data; and providing a processor to execute instructions to reconstruct a single three-dimensional model of at least a portion of a subject based on the acquired first image data and the second image data; wherein the first power characteristic is selected to be at least one of a first voltage of about 40 kV to about 180 kV and a first amperage of about 10 mA to about 500 mA; wherein the second power characteristic is selected to be at least one of a second voltage that is about 40 kV to about 60 kV different than the first voltage and a second amperage that is about 20 mA to about 150 mA different than the first amperage.
 2. The method of claim 1, further comprising: positioning the movable single x-ray source tube in a housing.
 3. The method of claim 2, further comprising: connecting the housing to a mobile cart operable to move the housing from a first room to a second room.
 4. The method of claim 1, further comprising: providing controls to move at least one of the movable single x-ray source tube or the housing during acquiring the first image data and the second image data.
 5. The method of claim 1, further comprising: acquiring the first image data and the second image data based on a selected physiological event of the subject and to acquire the first image data and the second image data of the selected physiological event of the subject.
 6. The method of claim 5, further comprising: gating the acquisition of the first image data and the second image data relative to the first selected position at both the first power characteristic and the second power characteristic to acquire the first image data and the second image data at the selected physiological event of the subject.
 7. The method of claim 1, wherein providing the processor to execute instructions to reconstruct the single three-dimensional model of at least the portion of the subject based on the acquired first image data and the second image data includes performing an algebraic iterative technique to alter a theoretical formed model of the subject to illustrate one of a first phase or a second phase of the subject.
 8. The method of claim 7, further comprising: selecting the first phase to be an arterial structure and the second phase to be a venous structure.
 9. The method of claim 1, wherein providing the processor to execute instructions to reconstruct the single three-dimensional model of at least the portion of the subject based on the acquired first image data and the second image data includes a difference of the first image data at the first power characteristic including a first x-ray absorption or x-ray scatter in a subject and the second image data at the first power characteristic including a second x-ray absorption or x-ray scatter in the subject.
 10. The method of claim 1, further comprising: providing controls to move at least one of the movable single x-ray source tube or the housing to vary a speed of movement of at least one of the single x-ray source tube or the housing over a period of time of the acquisition of the first image data and the second image data.
 11. The method of claim 10, wherein the varying speed of movement is dependent on a gating of the acquisition of the first image data and the second image data based on at least one of the timing of an injection of a contrast agent into the subject or a physiological event of the subject.
 12. The method of claim 1, wherein executing instructions with the processor to reconstruct the single three-dimensional model of at least the portion of the subject includes illustrating both a first phase and a second phase as separate anatomical portions of the subject.
 13. The method of claim 1, further comprising: providing a tracking system to track an instrument relative to a subject; and superimposing an icon representing the tracked instrument on the reconstructed the single three-dimensional model of at least the portion of the subject.
 14. The method of claim 13, further comprising: automatically registering the reconstructed single three-dimensional model of at least the portion of the subject at least by tracking the at least one single x-ray source tube or the housing.
 15. The method of claim 1, wherein executing instructions with the processor to reconstruct the single three-dimensional model of at least the portion of the subject further includes interpolating between the first image data and the second image data based on an amount of movement of the single x-ray tube between when the first image data was acquired with the first power source and the second image data was acquired with the second power source.
 16. An imaging system to acquire image data, comprising: a source system including, a single x-ray source tube, a first power system having a first power characteristic to power the single x-ray source tube to emit x-rays relating to the first power characteristic, wherein the first power characteristic is selected to be at least one of a first voltage of about 40 kV to about 180 kV or a first amperage of about 10 mA to about 500 mA; a second power system having a second power characteristic to power the single x-ray source tube to emit x-rays relating to the second power characteristic, wherein the second power characteristic is selected to be at least one of a second voltage that is about 40 kV to about 60 kV different than the first voltage or a second amperage that is about 20 mA to about 150 mA different than the first amperage; and wherein the source system is configured to be operated to switch between the first power system and the second power system to power the single x-ray source tube to emit the x-rays relating to the first power characteristic or emit the x-rays relating to the second power characteristic; a detector system positioned to detect the x-rays relating to the first power characteristic and the x-rays relating to the second power characteristic emitted from the single x-ray source tube; a processor to execute instructions to reconstruct a single three-dimensional model of at least a portion of a subject based on the detected x-rays relating to the first power characteristic and the x-rays relating to the second power characteristic emitted from the single x-ray source tube; wherein the source system and the detector system are configured to be positioned at a plurality of selected positions relative to at least the portion of the subject.
 17. The system of claim 16, further comprising: a control system included to control movement of the detector system and the source system; wherein the detected x-rays relating to the first power characteristic are a first image data; wherein the detected x-rays relating to the second power characteristic are a second image data; wherein the control system is configured to move the detector system and the source system to the plurality of selected positions relative to at least the portion of the subject to acquire a plurality of first image data and a plurality of second image data.
 18. The system of claim 16, further comprising: a gantry configured to enclose the detector system and the source system; wherein the detector system and the source system are operable to move around at least the portion of the subject within the gantry.
 19. The system of claim 17, further comprising: a pump operable to inject a contrast agent into the at least the portion of the subject.
 20. The system of claim 17, wherein the control system is operable to gate an image data acquisition and the movement of the detector system and the source system based on an injection time of a contrast agent into the subject.
 21. A method of acquiring image data with an imaging system, comprising: powering a single x-ray source tube with a first power source at a first power characteristic that is selected to be at least one of a first voltage of about 40 kV to about 180 kV and a first amperage of about 10 mA to about 500 mA, wherein the single x-ray source tube is configured to emit first x-rays based on the first power characteristic to acquire a first image data; powering the single x-ray source tube with a second power source at a second power characteristic that is selected to be at least one of a second voltage that is about 40 kV to about 60 kV different than the first voltage and a second amperage that is about 20 mA to about 150 mA different than the first amperage, wherein the single x-ray source tube is configured to emit second x-rays based on the second power characteristic to acquire a second image data; controlling an assembly of the first power source, second power source, single x-ray source tube with a detector to move around the subject during the acquisition of the first image data and the second image data; injecting a contrast agent into the subject at least prior to the acquisition of the first image data and the second image data; and operating a processor to execute instructions to reconstruct a single three-dimensional model of at least a portion of a subject based on the acquired first image data and the second image data.
 22. The method of claim 21, further comprising: displaying the single three-dimensional model with a display device.
 23. The method of claim 21, further comprising: acquiring a plurality of the first image data and a plurality of the second image data; wherein operating the processor to execute instructions to reconstruct the single three-dimensional model of at least the portion of the subject is based on the acquired plurality of the first image data and the plurality of the second image data.
 24. The method of claim 21, further comprising: moving the assembly further including a gantry to substantially surround at least the portion of the subject; moving the first power source, second power source, single x-ray source tube, and the detector within the gantry around the subject. 